There are various transmission line devices for use at RF and microwave frequencies. One such device is a signal transformer which changes the impedance and the phase of a signal which provides the necessary signal inversion needed for high efficiency push-pull amplifiers, mixers, dividers and other signal processing devices. The signal inversion is commonly referred to as a transformation of the signal from balanced to unbalanced or BALUN. A BALUN generally includes a single transmission line extending between and electrically insulated from a pair of ground planes. Another type of transmission line device is a hybrid coupler. A hybrid coupler generally includes a pair of transmission lines insulated from each other and extending between and electrically insulated from a pair of ground planes. Although all of the various transmission line devices must be constructed to have the desired electrical characteristics, it is desirable that these devices be relatively simple in design and construction, and relatively inexpensive. However, the low cost of such devices not only includes the cost of making the device, but also the cost of preparation and installation of the device in the next higher assembly. One technique for lowering the cost of installation is to be able to surface mount the device on a printed circuit board. Therefore, it is desirable to have transmission line devices which are capable of being surface mounted.